脱层材料与槽接式挫屈束制支撑的性能研究

挫屈束制支撑耐震性能优劣与否与脱层材料性能有密切关系,首先提出了一种估算脱层不完全因子的方法,利用4组分别使用不同脱层材料的挫屈束制支撑进行构件试验;研究结果表明以黏性橡胶作为脱层材料具有可靠性、经济性与优良的施工性。特别介绍了地震工程研究中心近期所研发的槽接式挫屈束制支撑,并通过3组实尺寸构件试验验证了其耐震性能;测试构件包含一组长度为12.5m,最大抗压强度超过16800kN,核心消能段应变量达3.5%的构件。试验结果表明,新研发的槽接式挫屈束制支撑经济效益极高,迟滞消能行为良好稳定,具有优良的耐震性能,各组试体于试验停止前所累积的总非线性变形量皆超过400倍斜撑屈曲位移量;研究亦显示,非线性结构分析软件PISA3D可准确预测其受力与变形反应。

Experimental Investigations of Unbonding Layers and Welded End-Slot Connection for Buckling Restrained Braces

Unbonding material is one of the most important constituents in a buckling restrained brace ( BRB ) .In this paper , a method for estimating the compressive strength adjustment factor for any given brace core strain is presented.Experimental investigations using four BRBs are conducted to examine the efficiency of four different unbonding materials in reducing the difference between the cyclic compressive and tensile strengths.Test results indicate that the chloroprene rubber is easy to install and effective in minimizing the strength differences between the cyclic peak compression and tension forces.The excellent performance of the welded end-slot buckling restrained brace ( WES-BRB ) is then illustrated through cyclic loading tests of three full-scale BRB components.It includes the test results of a 12.5 m long jumbo WES-BRB.Its peak compressive strength exceeded 16 800 kN and the maximum core strain reached 0.035.All WES-BRB specimens showed satisfactory performance with a very stable hysteretic response , very predictable axial stiffness , and sustained a cumulative plastic deformation greater than 400 times the yield deformation.